CVE-2026-73417

HIGH CVSS 4.0: 8.6 EPSS 0.55%
Updated Aug 14, 2026
jupyterlab
Parameter Value
CVSS 8.6 (HIGH)
Type CWE-79 (Cross-Site Scripting (XSS)), CWE-116 (Improper Encoding or Escaping of Output)
Vendor jupyterlab
Public PoC No

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 3.3.0 until 4.5.10 and 4.6.2, JupyterLab allows notebook settings to be shared and applied through an overrides.json file using the Import button in the Settings Editor. In packages/notebook-extension/schema/tracker.json and packages/notebook-extension/src/index.ts, the sideBySideLeftMarginOverride and sideBySideRightMarginOverride settings are not properly validated before being inserted into style content, allowing a crafted settings file to contain instructions that execute as code instead of only changing display preferences.

A user can import the malicious file, or an attacker with access to a shared settings location can plant an overrides.json that is applied automatically. The embedded code runs with the affected user's access and can read or modify notebooks and files and run code through the notebook server, including on a connected kernel. This issue is fixed in versions 4.5.10 and 4.6.2.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
Active
User action required

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption

CVSS Vector v4.0